Set up NIP-39 cryptographic identity

[franzaps]

(see my PR against NIP-39)

• grab already provided signature hashes
• give instructions in terminal to provide
  • signed message
    • keytool -importkeystore -srckeystore example.keystore -destkeystore example.p12 -deststoretype pkcs12
    • openssl pkcs12 -in example.p12 -nocerts -nodes -out privatekey.pem
    • echo 'Verifying that I control the following Nostr public key: "<npub encoded public key>"' | openssl dgst -sha256 -sign privatekey.pem | openssl base64 -A (replace pubkey with provided one)
  • public key
    • keytool -list -keystore example.keystore (check against earlier signature hashes)

[franzaps]

Should also prompt dev for auto-indexing, if they sign this they probably want to set and forget

[franzaps]

See #14